Mammal ancestors `not as puny as thought`

London: The common ancestor of modern mammals, which was often thought to be tiny, shrew like and living unobtrusively in the shadow of dinosaurs, may have actually been more like a small monkey in size, a genetic analysis has suggested.

Even though fossils indicate that some larger mammals shared the dinosaurs’ world, palaeontologists think that they all disappeared alongside the giant reptiles and only tiny mammals survived thereby giving rise to all modern forms.

However, Nicolas Galtier from the Institute of Evolutionary Sciences in Montpellier, France, begs to differ, New Scientist reported.

He and his colleagues used common features in the genomes of 36 modern mammals to sketch out the genome of the creature from which they had descended.

Reconstructing the detailed genome is impossible, but Galtier managed to recover two of its properties.

In modern mammals, these properties are correlated with body size and lifespan.

The results of Galtier’s study suggest that the ancestor of modern mammals weighed at least a kilogram, and lived over 25 years.